Patent Application
20060205543
The invention relates to a ball game or sport racquet, in particular a tennis racquet, according to the preamble of claim 1.
The object of the present invention is to provide for a ball sport or ball game racquet with improved playing characteristics. This object is achieved by a ball sport racquet according to claim 1. Further embodiments of the invention are the subject of the dependent claims.
One exemplary embodiment of the invention is described below with reference to the drawings, wherein:
The tennis racquet depicted in the drawings and generally designated 1 consists in the usual manner of an outwardly closed hollow frame or racquet frame, which forms a racquet head 2, a throat 3 comprising two bridges 3.1 and a racquet shaft 4 connecting to the throat 3. The racquet head 2 features the stringing or striking surface 6 formed by crisscrossing strings or string sections 6.1 on the part of the racquet also referred to as the main frame or racquet head frame 5.
The entire racquet frame, i.e. the racquet head frame 5, the throat 3 and its bridges 3.1 and the racquet neck or shaft 4 bearing the actual handle 4.1 are all part of the outwardly closed one-piece hollow frame, which or the supporting structure of which is manufactured in the known manner from a fiber-reinforced plastic (e.g. prepreg material). In
The special characteristic of the tennis racquet 1 consists in the fact that a plurality of rotation bodies or bearing elements 7 made of a suitable material, for example plastic, e.g. polyamide or POM and/or metal, are provided on the racquet head frame 5. The bearing elements 7 are provided with an eyelet-shaped section 7.1, which completely encloses the respective bearing element for pivoted mounting, and with a section 7.2, which protrudes somewhat over the inner side of the racquet frame head 5 and is located approximately in the plane formed by the stringing 6.
In the depicted embodiment, a total of six bearing elements 7 are provided on the racquet head frame 5, namely one bearing element 7 on each side of the longitudinal axis L at the head area of the racquet head 2 opposing the throat 3 and at a certain distance from said longitudinal axis and two bearing elements 7 on each side of the racquet head 2, i.e. approximately in the center between the throat 3 and the head area of the racquet head 2 located at a distance from said throat, wherein one bearing element 7 on one side of the racquet head 2 opposes one bearing element 7 on the other side of the racquet head in an axis direction perpendicular to the longitudinal axis L.
In the depicted embodiment, the sections 7.2 of the bearing elements 7 hold the strings or string sections 6.1 forming the stringing 6 in a manner resulting in two string sections 6.1 extending away from the section 7.2 of each bearing element 7. In the simplest case, this is achieved by the fact that at least one through bore hole 8 is provided in each section 7.2 of each bearing element 7 for inserting and holding the string.
In the depicted embodiment, the racquet head frame 5 has, in the area of the bearing elements 7 on its outer area 5.1 and on the two transitions to the inner area 5.2, a cylindrical outer geometry in relation to an axis that is tangential to the course of the racquet head frame 5, as indicated in
Each bearing element 7 has on its section 7.1 one opening 9, which forms a bearing surface bearing against the outer area 5.1 and which is adapted to the shape of this area, so that each bearing element 5 can pivot on the racquet head frame, namely on the axis that is tangential to the course of the racquet head frame 5.
Outside of the bearing elements 7 the strings or string sections 6.1 forming the stringing 6 are fastened to the racquet head frame in the usual manner, namely using cords or strands not depicted.
The racquet head frame 5, at least in the area where the bearing elements 7 are provided, at least on its outer surface, consists of a gliding and non-wearing material, i.e. in the form of a coating made of such a material. A suitable coating would be, for example, a PTFE coating.
In order to mount the bearing elements 7 on the racquet head frame 5, they are made of two parts, i.e. divided in the area of their section 7.1, as indicated by 10, so that each bearing element consists of one outer section 7.1.1 and one inner section 7.1.2, which also comprises the section 7.2. After assembly, the two sections 7.1.1 are connected with each other in a suitable manner, for example by a screw and/or snap-on connection.
In the depicted embodiment the bore hole 8 is a through hole, the axis of which is parallel to the longitudinal extension of the racquet head frame, so that the two string sections 6.1 extending away from the respective bearing element 7 are located to the side of section 7.2. Other designs are also conceivable. For example, it is also possible to provide channels instead of the through hole 8, so that the string sections 6.1 extend away from the face 7.2.1 of the respective bearing element facing away from the racquet head frame 5. As can also be seen in
The essential advantages of the racquet 1 are the effective uncoupling between the stringing 6 and the racquet frame and a large-surface transfer of the force of the strings in the racquet frame. A further advantage consists in the greater progression of the stringing 6 or of the string bed. For example, in the event of deflection of the bearing elements 7 when hitting a ball, this will automatically cause additional elongation or tensioning of the strings or string sections 6.1. This enables the use of a lower string stiffness. Upon contact with the ball, the ball is initially absorbed by a softer string bed with less deformation of the ball, and the string bed progressively stiffens to an extreme degree with the increasing deflection of the bearing element 7.
A further essential feature is that the above advantages are achieved with no weakening whatsoever and therefore no limitation of the strength of the racquet head frame, since the racquet head frame is designed also in the area of the bearing elements 7 with the large cross section necessary for strength and stiffness and no holes, notches or other weakening of the racquet frame are necessary for mounting the bearing elements 7. A further essential advantage is that the outwardly closed hollow profile of the racquet frame is also maintained in the area of the bearing elements.
The invention was described above based on one exemplary embodiment. It goes without saying that numerous modifications and alterations are possible without abandoning the underlying inventive idea upon which the invention is based.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2005 011 728.7 | Mar 2005 | DE | national |
| 10 2005 015 495.6 | Apr 2005 | DE | national |
